Air-inflated cushioning mediums having an air-encapsulating portion formed between overlying resin sheets have been widely used so far. They may protect articles to be protected against impact from outside by forming an air-inflated portion partially or entirely around the article.
An air-inflated cushioning medium has been proposed, for example, by Japanese Utility Model Application Laid Open No. H06-35973. This proposes a cubiform cushioning medium comprising an opening for containing an article to be protected, which can be produced by steps of sealing airtight plastic films together for separate air-encapsulating cells and then forming said plastic films into a shape like an envelope.
In the bottom part of this cubiform cushioning medium, the above-mentioned cells are arranged to communicate with each other so that air in the cells may flow therebetween.
However, when the opening of the medium contains something damageable such as bottles or a relatively heavy article like electric appliances, said cubiform cushioning medium is incapable of absorbing any impact in case of dropping or other manners only with the air-contained cells, resulting in breaking the article by way of burst of the cells and airflow therein to cause direct impact against said article.
In view of the above-described problems, a first object of the present invention is to provide a cubiform cushioning medium which puts weight on protection around the bottom portion in particular, and is capable of protecting a damageable article like a bottle sufficiently.
Furthermore, a second object of the present invention is to provide a cubiform cushioning medium capable of protecting a relatively heavy article sufficiently.